FOURTH AMENDMENT FRIDAY FUNDAMENTALS - CASE #2: U.S. v. Cortez

 Posted on September 26, 2025 in Legal

I am pleased to present our second case for  Fourth Amendment Friday Fundamentals, where we take a brief look at landmark cases involving Fourth Amendment decisions that impact our work as defenders of justice for those citizens accused of DUI/DWI and traffic offenses across the country.

Today we are looking at US v. Cortez, 449 U.S. 411 (1981).  Where Delaware v. Prouse, 440 U.S. 648 (1979) (our case from last week) gave us the requirement that there must be articulable reasonable suspicion for a vehicle to be stopped, Cortez addressed "the elusive concept of what cause is sufficient to authorize the police to stop a person."

Cortez involved a case where Border Patrol agents stopped a pickup truck they suspected of illegally transporting a large group of individuals into the United States from Mexico.  The suspicion was based, inter alia, on location, time of day, and the make and model of the pickup.  Cortez, the driver and owner of the pickup, challenged the basis of the stop, arguing that the officers lacked objective indications that he was engaged in criminal activity.  The trial court denied Cortez’s motion to suppress, but the Ninth Circuit reversed, finding "far too many innocent inferences" to justify the stop.

The Supremes granted review, and reversed.

While the Court initially struggled to define "reasonable suspicion," they eventually declared the following:

"[T]he essence of all that has been written is that the totality of the circumstances —the whole picture—must be taken into account.  Based upon that whole picture, the detaining officers must have a particularized and objective basis for suspecting the particular person stopped of criminal activity."

In reversing, the Court relied heavily on the idea that officers are able to rely on their training and experience to deduce things that might elude the untrained observer.

In sum, this decision established that sufficient cause for a traffic stop is determined by a review of "all of the circumstances," or "the whole picture" as established by "objective observations."

Stay tuned for more Fourth Amendment Friday Fundamentals.